Chemical Mechanical Polishing (CMP) is one type of process used in the manufacture of semiconductor devices. CMP is a process used to smooth and planarize the surfaces of wafers using a combination of chemical and mechanical forces. Integrated circuit (IC) dies in wafer form are placed into a chamber of a CMP apparatus and are planarized or polished at various stages of a manufacturing process. CMP processes may be used to form planar surfaces on dielectric layers, semiconductor layers, and conductive material layers of a wafer, for example.
CMP apparatuses typically have a rotatable platen with a polishing pad attached thereto. In some CMP processes, a semiconductor wafer is placed upside down against the polishing pad using a predetermined amount of pressure. A liquid dispersion referred to as slurry that contains chemicals and microabrasive grains is applied to the polishing pad during the CMP process while the wafer is held against the rotating polishing pad. The wafer is also rotated in some applications.
Although existing devices and methods for a CMP process have been generally adequate for their intended purposes, they have not been entirely satisfactory in all respects. Consequently, it would be desirable to provide a solution for polishing wafers in CMP apparatuses.